Deborah Robertson

Professor, Biology
Department Chair, Biology

My research program investigates the physiological ecology and the evolution of nitrogen metabolism in marine diatoms and other ecologically important groups of marine algae. In many marine environments, nitrogen availability is an important factor regulating primary productivity. By characterizing the enzymes and regulatory pathways involved in nitrogen metabolism, this work will contribute to our understanding of the coupling between nitrogen metabolism and productivity.

The assimilation of inorganic nitrogen (N) into organic compounds is a key process regulating the growth and productivity of photosynthetic eukaryotes. Diatoms are unicellular photoautotrophs that contribute significantly to global biochemical cycles. They exhibit rapid growth in response to increases in N availability, which in marine ecosystems, varies over several spatial (meters to kms) and temporal scales (hours to months). Thus, the ecological success of diatoms can, in part, be attributed to their ability to rapidly sense and respond to fluctuations in N source and supply.

In all living cells, the regulation of gene expression is a multifaceted and dynamic process. Cells integrate intrinsic and environmental signals into multiple regulatory pathways allowing for coordinated gene expression and cellular function. While there has been much focus on patterns of coordinated gene transcription, there are now examples from bacteria, kinetoplastids, plants, fungi, and animals of coordinated post-transcriptional regulation of mRNAs encoding functionally related proteins.  This project explores the general hypothesis that post-transcriptional regulation of genes involved in N transport and assimilation in marine diatoms allows for rapid metabolic response to perturbations in nutrient source or supply and is mediated by changes in mRNA stability.

The evolutionary history of several algal lineages is complex and riddled with endosymbiotic events, gene duplications, gene transfers, and gene losses.  These genomic alterations would have required modification of metabolic and regulatory pathways and suggest that the regulation of metabolic pathways will vary among of the algal lineages. We are exploring the molecular evolution of nitrogen assimilating enzymes in select lineages of algae.  This research will contribute to our understanding of the cellular processes that regulate oceanic productivity and of the impact of anthropogenic nutrients on marine ecosystem. The work should also contribute to our understanding of the evolution of nitrogen metabolism in photosynthetic eukaryote.

Degrees

  • Ph.D. in Molecular Genetics and Cell Biology, University of Chicago, 1997
  • M.S. in Biology, California State University, Long Beach, 1988
  • B.A. in Biology, Kalamazoo College, 1981

Affiliated Department

Biology

Scholarly and creative works

Awards and grants

  • Regulation of nitrogen assimilation in marine diatoms: Investigation of the importance of post-transcriptional processes

    National Science Foundation